reverse dns and broken delegations

[Pui Ng]

I think I have a problem with how reverse is being delegated to me:
* root nameservers delegate 238.215.216.in-addr.arpa to
  ns.trivergent.net and ns2.trivergent.net
* trivergent.net delegate 238.215.216.in-addr.arpa to ns.plusweb.com
* ns.plusweb.com delegates 104.238.215.216.in-addr.arpa to me,
  ns.adjani.net

When I do ptr lookup of 104.238.215.216.in-addr.arpa, it seems to be
broken at trivergent.net.
* ns.trivergent.net returns an NXDOMAIN for that pointer; it also
correctly returns ns.plusweb.com as the authoritative nameserver.  I
suspect this means that it has been configured as a master for the zone
and/or has a SOA for the zone, so it tries to find the results of the
query anyway (but has no records at all).  The ripe zone checker lists
multiple problems with this zone - see
http://www.ripe.net/cgi-bin/nph-dc.cgi?primary=&ns0=ns.trivergent.net&ns1=ns2.trivergent.net&zone=238.215.216.in-addr.arpa&Submit=Submit

* To make matters more complex, ns2.trivergent.net does recursively
search for the ptr record, and returns a result.  this makes reverse
resolution work about half the time.  also, this behaviour is not what i
want - i want queriers to query my server directly.

* ns.plusweb.com returns ns.adjani.net as the name server record for
104.238.215.216.in-addr.arpa.  however, it also returns the result of
the ptr lookup, which is not what i want either (i want resolvers to
query my nameserver directly)

How should this be configured?  I see some possibilities.  Please also
advise me if I'm being very stupid and am treating this all wrong.

1. Clearly, it would be ideal if the root nameservers were to delegate
238.215.216.in-addr.arpa directly to ns.plusweb.com; this may not be a
solution that I can get my isp and their isp to implement, however.  If
not, 2. or 4. might have to do... or is there any other way to do this?

2. I need to find a way of making the trivergent nameservers simply
return ns.plusweb.com as the authoritative name server that all
resolvers should refer to?
 Is this in fact what the stub type is used for?  If so, would the
following in both of trivergent's nameserver's named.conf work?
     zone "238.215.216.in-addr.arpa" in {
       type stub;
       file "slave/216.215.238";
       masters {216.215.238.2;};
     }

3. Would the correct way for plusweb to delegate to me then be to have
this in named.conf:
     zone "238.215.216.in-addr.arpa" in {
       type master;
       file "master/216.215.238";
       recursion no;
     }
 and to have the usual in "master/216.215.238" :
     ...
     103.238.215.216.in-addr.arpa. IN PTR some.domain.com.
     104.238.215.216.in-addr.arpa. IN NS  ns.adjani.net.
     ...

3. Alternatively, ns.plusweb.com run as a 'hidden master' server with ns
and ns2.trivergent.net as the public authoritative slaves.  ie, have
ns.plusweb.com put this in "master/216.215.238":
     ...
     @ IN NS ns.trivergent.net.
     @ IN NS ns2.trivergent.net.
     ...
     104.238.215.216.in-addr.arpa. IN NS ns.adjani.net.
     ...
 and have this in named.conf on *.trivergent.net
     zone "238.215.216.in-addr.arpa" in {
       type slave;
       file "slave/216.215.238";
       master {216.215.238.2;};
       recursion no;
     }

Is there some better way to do all of this?